I only have two memories dat have de sky in dem. In both of dose, de entire sky is clouded and it's raining. Dat's what it's like in de Junkyard . . . de only tings dat go on forever dere are rain and war. And de Embryon, of course.
As for de sky in Nirvana, I don't have any memories of dat yet. Mebbe dere's a sun . . . de solar noise is a lot worse dan it was in de Junkyard.